1. Field of the Invention
The disclosures herein relate to peripheral devices including an image forming apparatus provided with an authentication function utilizing near-field data communication, a network system in which such peripheral devices are connected through a wired or wireless network, a communication processing method involving authentication of the peripheral devices, and a communication control program for causing a computer to perform communication control implemented by the communication processing method.
2. Description of the Related Art
In recent years, IC cards or the like utilizing a near-field communication technology (hereinafter referred to as NFC) has been increasingly used as ID cards in employee ID cards, student ID cards, commuter passes, mobile wallets, and the like for identifying individuals. The standard referred to as NFC is a communication protocol that uses electromagnetic induction in a 13.56-Hz frequency band, and is used for close-range communication with relatively low speed. A maximum range of communication is approximately 10 cm. This standard is defined by NFC IP-1 (ISO/IEC18092) and NFC IP-2 (ISO/IEC214841). The functions of NFC include a card emulation function, a reader/writer emulation function, a inter-terminal communication function, and also include extended functions such as an NFC inter-terminal pairing function, and a Bluetooth handover function.
The card emulation function allows an operation as a noncontact IC card, thereby serving as IC cards and tags conforming to the FeliCa standard, the TypeA standard, the TypeB standard, and RFID (i.e., ISO15693 standard). The reader/writer emulation function allows an operation as a reader/writer, thereby making it possible to read and write IC cards and tags conforming to the above-noted standards. With this function, information is transferred by holding a mobile phone or PDA (personal digital assistant) with an NFC-embedded smart-card chip over an IC or tag conforming to these standards. The inter-terminal communication function allows data exchanges between NFC-compliant devices. The NFC inter-terminal pairing function allows only pairing or authentication between NFC-compliant devices to be performed by NFC, and allows vast amount of data to be transferred by use of some other high-speed standard after the pairing or authentication. The Bluetooth handover function allows only pairing or authentication between NFC-compliant devices to be performed by NFC, and then allows a vast amount of data to be exchanged by use of Bluetooth. There is a similar function referred to as a Wi-Fi handover function.
In the field of computer technology, NFC-equipped IC cards are utilized to limit the people who can use a particular device, and are also utilized for pairing or association in a network. There have also been suggestions that NFC may be utilized not only for computers but also for security-conscious network pairing or association with respect to office equipment having multiple functions such as copier and facsimile functions.
The use of wireless transmission results in a radio wave reaching a wide area. Thus, wireless communication has a problem in that security is undermined in data transmission between devices unless a recipient device is correctly specified. NFC with a communication range of approximately 10 cm is not free from this problem. In consideration of this, a digital certificate that is stored in a protected area referred to as a token is utilized in IC cards or the like. This token is specifically referred to as an NFC token when used in NFC.
There are various types of NFC tokens. In a majority of these types, information required to use a device is read from a memory area within an NFC token. An authentication process is then performed through IC-card authentication, pairing-encryption-based pairing, or association for establishing a safe communication path by exchanging and sharing information about an encryption method and an encryption key, for example, prior to the commencement of communication, thereby attaining high-level security. An additional function may be provided to perform mutual authentication between the NFC token and the device at the time of accessing the above-noted memory area that stores information. Setting information necessary to establish network connection and information necessary to authenticate individuals are stored in the NFC token, and may be acquired by the device. An area for storing the information in the NFC token may vary depending on the function to be used.
Further, an NFC token which stores certificate information has also been used. There may be cases in which the certificate is used as a trigger for security functions provided for the function to be used. There has been a suggestion that the above-noted arrangement is used to provide security for a communication path of network functions or to check whether electronic data is safe and legitimate by using a signature attached thereto.
A technology relating to such security systems is disclosed in Patent Document 1 (Japanese Patent Application Publication No. 9-223210). This technology is aimed at achieving the safe management of keys that are used to authenticate digital signatures or the like in a network. A public key and private key used in a public key cryptosystem required for the RSA signature law or the like are stored in an IC card as a public key certificate and a private key. The public key certificate is comprised of a public key and a digital signature for the public key issued by a CA (certificate authority). A sender receives the IC card from the CA through an offline channel, and inserts the IC card to a network terminal to create a digital signature by use of the private key. A message accompanied by the digital certificate and the public key certificate are sent to a recipient. The recipient checks the authenticity of the CA's signature on the public key certificate by use of the CA's public key that is received through a different channel. Then, the sender's signature is authenticated by use of the sender's public key that has just been authenticated.
Patent Document 2 (Japanese Patent No. 3761432) also discloses a relevant technology. This technology is aimed at reducing the load required for authenticity check of a user's CA certificate and also aimed at preventing a theft of a CA certificate that is being transmitted. An IC card that stores a CA certificate and identification information is distributed to a user. An authentication system that keeps authentication system certificates corresponding to respective identifications reads the IC card through a user terminal. Upon receiving the identification information, the authentication system issues an authentication system certificate corresponding to the received identification information. The user checks the authenticity of the authentication system by use of the authentication system certificate.
Patent Document 3 (Japanese Patent Application Publication No. 2009-159053) also discloses a relevant technology. This technology is aimed at properly managing digital certificates in an environment in which a plurality of applications using digital certificates are in existence. An information processing apparatus having a plurality of applications that perform communication by use of digital certificates includes a management unit that manages links between these applications and digital certificates. The digital certificates are properly managed through an arrangement that a given application uses a digital certificate linked thereto by the management unit.
Patent Document 4 (Japanese Patent Application Publication No. 2005-260759) also discloses a relevant technology. This technology is aimed at providing an electronic signature and a signature check system that does not need to have a certificate, thereby eliminating problems associated with a processing capacity and processing load. On behalf of and upon instructions from client terminals, a proxy apparatus keeps certificates for users (i.e., clients) who use these client terminals. In order to prove the authenticity of a sender's signature to a recipient, the sender's certificate or a set of the sender's certificate and the certificate authority's certificate is presented to the recipient. At the time of checking the recipient's electronic signature, also, a certificate or the validity of the certificate are checked. Further, the results of the check are reported through encryption to the sender. The client terminal includes a processing unit for encrypting and decrypting the sender's electronic signature and a recording medium for storing an encryption key or a decryption key for the sender's electronic signature.
In the related arts described above, an IC card is used as a private key. Alternatively, an IC card that stores a CA certificate and identification information is used. Alternatively, a management unit is provided that manages links between applications and respective digital certificates. Alternatively, on behalf of and upon instructions from client terminals, a proxy apparatus keeps certificates for users (i.e., clients) who use these client terminals. The client terminal includes a processing unit for encrypting and decrypting the sender's electronic signature and a recording medium for storing an encryption key or a decryption key for the sender's electronic signature.
In these technologies, one certificate for one device or certificates for respective functions of this device are installed and stored in the device's RAM disc or HDD. These certificates are used with respect to the device or functions, thereby encrypting a communication path or authenticating electronic data.
In such authentication methods, each certificate is unique for each device or each function. When this certificate is leaked and misused, there is a risk of the security of the device or functions being undermined. For example, a certificate specific to a device and used in common for the functions of the device may be installed in the device. A malicious user may then steal the certificate directly from the device or through a network. In such a case, information may be leaked or tampered with through the misuse of the certificate.
Accordingly, it may be desired to prevent such misuse and to improve network security and data security for each individual using a device.